


Variables

by Sherlock_a_Khan



Category: Sherlock (TV), Sherlock Holmes & Related Fandoms
Genre: M/M
Language: English
Status: Completed
Published: 2014-04-23
Updated: 2015-03-25
Packaged: 2018-01-20 12:44:45
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 6
Words: 11,217
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1510934
Author URL: https://archiveofourown.org/users/Sherlock_a_Khan/pseuds/Sherlock_a_Khan
Summary: <blockquote class="userstuff">
              <p>Sherlock likes to experiment using John as the subject. A little bit of Johnlock smutty goodness in every chapter.</p>
            </blockquote>





	1. Chapter 1

It’s well into the late morning when John realizes that he hasn’t heard Sherlock get up yet, his breakfast that Mrs. Hudson made getting cold on the table. He wonders what time the detective finally got in, his latest case causing him to be in and out at all hours of the day over the past week.

He wonders how the other man can go on the way he does, on too little sleep, with no food in his system. He tries to keep him on track, as does Mrs. Hudson, but there’s no controlling the man when he’s in the grips of a case the way he is now.

There’s a quiet creak on the floor as John makes his way down the hallway to Sherlock’s room, the door partially open and the light from the hallway spilling into the darkness. The flat is otherwise quiet except for the soft sound of Sherlock’s sleepy breathing, and John quietly pushes the door further open, taking a step inside.

His breath catches immediately at the sight of Sherlock, the consulting detective lying flat on his back, one hand splayed over his stomach while the other is tucked behind his head, his breathing steady with sleep. 

His sheets only barely cover one leg, the remainder of the material bunched up beside him. Sherlock's cock is hard and leaking pre-cum, several drops gathering on smooth skin as the head hovers just above Sherlock’s stomach. 

John feels his own cock stiffen and strain against the material of his pants at the sight, and he unconsciously begins to start rubbing the rough material. He takes a step back until he is resting against the wall, his hands shaking as he releases the button and pulls down the zipper of his jeans, reaching into his pants and pulling his straining member out. 

He bites his lip, hard, to keep from moaning as he squeezes the shaft and begins a slow rhythm, every nerve fiber feeling like it's on fire. Sherlock's cock twitches almost as if John had been touching it instead of his own, and he can’t help but let his gaze travel up the smooth expanse of skin, the steady rise and fall of his chest, the movement in his throat as the detective swallows.

John can’t help but imagine the feel of Sherlock swallowing as he takes the length of his shaft into his mouth, John’s hand slowly moving up and down his cock as he imagines the thought of seeing Sherlock’s lips wrapped tightly around him.

John is so wrapped up in the imagery that he doesn’t notice Sherlock’s eyes drift open until it’s too late, his hand stopping mid-pump as his breath catches. He can’t bring himself to even blink as he watches the other man slowly pull himself up in bed, his eyes on John as if his mere gaze were pinning the doctor to the wall.

In seconds Sherlock is standing in front of John, their gaze locked as the detective pushes John's hand away, grabbing his shaft and squeezing it hard and forcefully. John's head falls back at the sudden jolt, hitting the wall, and he's not quite sure if it's the head trauma or the long slender fingers that are fisting and stroking his cock that makes him see stars.

Sherlock uses his other hand to brace himself against the wall next to John's head, and the doctor moans as he feels Sherlock's erection brushing against his thigh, the pre-cum warm on his skin. The detective's breath is hot on John's neck, his breath catching in his throat as the other man nips at his skin, the sudden sensation tingling down his spine when the pain is followed by the stinging sensation of his tongue. 

"Sherlock."

The name is said on a breath, John not even sure if it was loud enough to be heard, and he feels his heart racing as Sherlock speeds up his rhythm, his body pushing closer and closing any remaining distance. The only space between them allows the movement of Sherlock's hand, John attempting to snake his between them to grab hold of the cock that continues to rub against his thigh, but Sherlock forcefully grabs his wrist, pinning it to the wall above him, his grip tight and relentless.

John doesn't attempt the same move with his other hand, instead grabbing the back of Sherlock's neck as he thrusts his hips forward, his eyes closed and pinpoint lights flashing behind his lids. He pushes his head further back against the wall, tilting his chin up and allowing full access to the sensitive skin of his neck as Sherlock nips and sucks at it.

John can feel himself on the verge, the muscles in his groin tensing up as he pants out Sherlock's name repetitively, the detective silent as he continues his assault on John's neck, his hand speeding up, pumping faster.

It’s over with a flash of light, John feeling blind and heavy, his legs threatening to give out from under him as he tries to regain control of his breathing, of his heart that’s about to beat out of his chest. His hand that was previously around Sherlock’s neck feels sticky, confusion starting to creep into his mind as he slowly allows his eyes to open, taking in his environment.

His heartbeat seems to pick up tenfold as he notices that the lights are on in the room, his eyes settling on the perfectly made bed in front of him. He blinks away the confusion as his gaze slowly drifts to the doorway, and he feels the air escape his lungs when he sees Sherlock standing there, his shirt buttons straining against his chest, the faintest of bulge hiding within the material of his slacks.

“John.”

“Sherlock. I- I can explain.”

John realizes there’s very little explanation needed as Sherlock’s eyes travel down his body, and it’s then that John realizes he’s still holding his cock in his hand, cum moistening his knuckles and the floor below.


	2. Chapter 2

**Notes for the Chapter:**

> 110% happier with this chapter than the last. Thx for the kudos and reviews.

John sees Sherlock very little over the next few weeks, spending extra hours with patients and getting back to the flat just in time to see the consulting detective getting into a cab and disappearing onto the trails of whatever case he’s working on this week. He could say it’s a coincidence that they seem to come and go just at the right time to miss each other but he would be lying as he sits in Speedy’s, waiting.

Some nights he’s too tired to wait, however, and finds reasons to avoid Sherlock when he makes it upstairs to find the detective sitting in his chair, reading a newspaper or playing the violin. Showers become a little longer, he goes to sleep sooner, but eventually he knows that what Sherlock walked in on will have to be spoken about. They’re grown adults after all, and the explanation is simple. Or not simple. John is unsure what exactly the state of the explanation is because it still doesn’t make sense in his head, his interest in sex never quite venturing to the male side of the anatomy before.

Perhaps Mrs. Hudson knew more than John believed, or perhaps she just likes to play it fast and loose with her daily smoothers. John thinks that perhaps it’s the latter as he finally gives up on the waiting game one evening, ascending the stairs to the flat as he hears the old woman laughing to herself. He makes a mental note to give the land lady a good check-up the next time he’s free as he closes the door behind him, the sound of her laughter being replaced by the quiet of his own flat.

“Sherlock?” His search for the detective is met with silence as John’s eyes scan the room, finding everything in its typical place. The doors to the restroom and Sherlock’s room are open as usual, and John lets out a quiet sigh of relief at the thought of not having to deal with the detective tonight, the past few days of busy work bringing down his energy as he trudges off to the bathroom for a shower.

He makes it a quick one, toweling his hair off before grabbing his robe from the hook on the back of the door. The flat is still silent as he makes his way up to his room, turning the light on only to find himself grabbing his chest and kneeling over, trying to calm his startled nerves.

“Jesus Christ Sherlock, what the hell are you doing in here?”

Sherlock is sitting in the middle of John’s bed with his back against the headboard and his legs crossed at the ankles. His eyes are closed as he rests his laced fingers over his lap, obviously not as startled as John currently is.

“You’ve been avoiding me since your masturbatory activities in my room.” Only Sherlock can make a sexual act sound so scientific and John can’t help but roll his eyes at the detective, surprised that he even knows what the word means. He doesn’t exactly appear to be the type wanking it every night while searching through porn videos of busty babes or even twinks for that matter. Not that John knows what gets him off other than four serial suicides and a note. Perhaps he can have his own name added to that list, the thought fleeting as he shakes his head and returns his attention back to the matter at hand.

“I haven’t been avoiding you, I’ve been busy.” They both know it’s a transparent lie, but John isn’t willing to surrender that easily. Sherlock doesn’t have to say anything, the look he’s giving John speaking loudly as he clears his throat and takes a deep breath.

“You’re attracted to me John, you have been for some time but I suspect that you just recently realized it. You’ve been looking at an increased amount of porn on your laptop, predominantly blondes with long hair which is a change from the short haired brunettes that you used to enjoy. I suspect they remind you too much of me, and you’re in the process of trying to convince yourself that you’re not gay while trying to figure out if I am.”

“Are you?” The words slip out before he can stop them but Sherlock seems unfazed as he slides off the bed, the buttons of his dress shirt straining against the fabric and drawing John’s gaze to them. It’s not subtle, but neither is the increase in John’s respirations as he finds Sherlock standing close enough that he can feel the other man’s body heat invading his space.

“Is this how you imagined it John? Did I have you against the wall, touching you, making you moan?”

“Oh god yes,” John’s breathing is coming out in deep rapid succession, his eyes closed tight, his hands limp at his side as he suddenly finds himself backed against the wall, the fabric between them suddenly too much.

Sherlock feels John’s erection rub against his clothed crotch as he takes another step forward, grinding his hips into the older man and eliciting a deep moan from somewhere deep in his chest. He whispers in John’s ear to open his eyes, the other man complying as he finds Sherlock staring at him intently, his hand slipping between them and under John’s short robe, palm rubbing against his erection in slow deliberate movements.

“Is this it John? Is this what you want?” It’s almost as if Sherlock is tempting John, wanting his flat mate to take control of the situation, and the thought only proves to make him more aroused, his cock feeling thicker than usual as Sherlock finally wraps his long fingers around him.

Their staring battle is becoming heated as John forces himself to hold the gaze of the other man, his hips bucking ever so lightly into Sherlock’s hand as he wanks him, his hand smooth as it slides back up his shaft, his thumb rubbing circles on the tip, spreading the pre cum before sliding back down in a tight fist. 

John feels himself reaching the edge with each passing second but he isn’t quite ready to give it up yet, not with a simple wank, and he finds himself finally challenging Sherlock as he moans “use your mouth”, a smirk playing on the detectives lips almost as if he knew what John was going to say before John could even formulate the thoughts himself.

He expects Sherlock to object, to tell him that he’s only willing to play into his fantasy so much, but no words are spoken as Sherlock sinks to his knees, fist still encompassing John’s shaft as he comes face to face with the head, his tongue flicking out for a preemptive taste. That one touch alone is almost enough to send John over the edge, his hips bucking forward and his cock rubbing against Sherlock’s lips. Hands press against his hips, his ass against the wall as he’s held firmly in place to prevent further unwanted movement, Sherlock taking a deep breath through his nose before he fully envelops John’s cock in the warmth of his mouth.

Teeth scrape ever so gently along the underside of John’s cock as Sherlock pulls back, the move calculated, almost as if it had been practiced. The thought of one of Sherlock’s experiments consisting of him deep throating certain phallic shaped fruits and vegetables doesn’t help John’s current attempts at staving off his orgasm any, his hands finding their way to the curls of Sherlock’s hair as he finds himself moaning the detectives name.

When a hand slides from his hip to cup his balls he knows his time is limited, significantly so as he feels his body stiffen. Sherlock knows it to, can feel it in the pressure John is putting against the hand still pinning him against the wall, trying to fuck his mouth into oblivion. His resolve holds steady though, doing the fucking himself as he feels the tip of John’s cock hitting the back of his throat, his nose being tickled by the curled hairs brushing against it each time he deep throats the older man.

John is waiting for the moment that Sherlock starts gagging, feeling himself slipping deeper into that skilled mouth with each passing moment, but it doesn’t happen and quite frankly he can’t be bothered by the thought any longer, his fingers unintentionally pulling at the curls grasped within his fingers. The action causes Sherlock to moan, the vibrations being transmitted through John’s shaft as he feels his cock pulsating, ribbons of cum disappearing within the confines of Sherlock’s throat.

It takes several moments to catch his breath, to convince his legs to continue holding his weight as they tremble, and he almost expects to find himself in another fantasy when he opens his eyes, instead finding Sherlock pulling himself up to his feet, wiping the corners of his mouth and straightening his suit.

“Sherlock, that was-“ he can’t quite find the words to describe it, but he imagines he doesn’t have to, Sherlock looking at him knowingly.

“Yes, well then, I suppose now that we’ve got that out of the way you can stop this rubbish about avoiding me. We’ve got a case John, two bodies and a full skeleton, Lastrade is wai-“

“Did you just give me a blow job so that I would work a case with you?” Sherlock is cut off suddenly by the angry accusation, John’s face turning various shades of red. The question is met with a sarcastic roll of the eyes as if the answer was the most obvious thing in the world, and how dare John not realize that this is exactly something that the detective would do?

That thought makes him even more heated, that he didn’t see this coming in the first place, and he finds himself pushing the detective out of his room, Sherlock looking almost confused as to why John is mad in the seconds before the door slams in his face.

**Notes for the Chapter:**

> More coming eventually.


	3. Chapter 3

**Notes for the Chapter:**

> More thanks for the kudos.

They sit across from each other in their respective chairs, Sherlock sitting with one leg crossed over the other and a newspaper resting in his lap. He seems focused on whatever he’s reading, ignoring the clicking of keys as John sits across from him, typing away at his blog. Sherlock can only imagine what the blogger is typing, seeing as how he refuses to work any cases with him, and he makes a mental note to investigate John’s laptop later when he’s alone. 

He figures his flat mate is already mad at him, he’s got little to lose and only more glares to gain each time they’re within general vicinity of each other. Even Lestrade is starting to wonder what’s causing the domestic between the two, Sherlock seeming a little more testy on cases, not only telling Anderson to leave the room, but even physically pushing him out on two separate occasions. 

He’s tried to apologize, although he’s not quite sure what he’s apologizing for. John was clearly fantasizing about him, Sherlock watching him intently almost the whole time, trying to decide whether or not this was information that needed to find a place in his mind palace. After several moments he decided that it wouldn’t hurt to have the information, and was about to make a move to alert John of his presence, but as he took a step forward John’s breath caught in his throat and he was coming, his hands and Sherlock’s bedroom floor becoming coated in his semen.

He figured he was doing the blogger a favor, making his fantasy a reality. He did seem to enjoy it immensely, if the considerable amount of semen Sherlock swallowed was anything to go by, or perhaps that was the problem after all. Perhaps John isn’t keen on blow jobs; perhaps he was imagining something else. Hand job? With the things Sherlock has seen in John’s search history, he hardly imagines the doctor being so vanilla about his sexual preferences. “So what is it?!”

Sherlock’s last thought is verbalized rather aggressively before he can stop it, his gaze leaving his newspaper long enough to see John staring at him from a few feet away, his hands still hovering over the keyboard of the laptop as his eyebrows knit together in confusion.

“What is it?” Sherlock considers very briefly of ignoring his own sudden outburst but decides better of it, rather wanting an answer as to why John is so mad at him.

“What is what?”

“You were in my room rubbing one off to the thought of me, John. I gave you what you wanted, and you appeared to be very much enjoying yourself.”

“You think I’m upset about you giving me a blowjob? Are you really so dense, Sherlock?!” Sherlock actually seems a little hurt by the remark, and John quickly realizes that Sherlock doesn’t actually get it at all.

“The only reason you did it was so I would work a case with you!”

“Boys, neighbors!” The sound of Mrs. Hudson’s voice breaks through the tension as she walks into the flat carrying a tray of tea and biscuits, setting it on the table between the two men before moving to stand near the fireplace.

“What is the domestic over this time?”

John can only imagine the field day the landlady would have knowing their domestic was over Sherlock giving him a blow job, although he imagines she already believes it’s a regular occurrence what with the looks and comments she’s always making about the two.

“It’s nothing, Mrs. Hudson. I didn’t mean to raise my voice. We’re just having a bit of a tiff over a case.” She looks between the two, John giving her a fake smile while Sherlock just glares at John, hardly noticing the presence of the woman in the room at all.

“Well, you two settle it, can’t be having the neighbors complaining.” And with that she’s gone, leaving the door open behind her as usual.

“I didn’t do it so you would work a case with me. You’ve worked plenty of cases without receiving sexual favors, why would I expect that was the criteria for your assistance now?”

John opens his mouth to respond but quickly realizes that Sherlock has a point. He looks away briefly, feeling guilty, and when he turns back he finds Sherlock’s gaze focused back on the paper in his lap, knowing he’s won.

The room is thrust back into silence, John staring at the screen of his laptop but not really focusing on it, occasionally stealing glances over at Sherlock who seems content now that he’s got the answer to his question and has put John in his place. Each time he glances over at Sherlock he finds his gaze lingering a little longer on the detective’s lips, his mind flickering back to the images of him on his knees in front of him.

John shifts the laptop in his lap, feeling himself starting to get aroused at the images he’s pushed to the back of his mind, knowing that if he thought too long about them over the past few days he would forget that he was angry at Sherlock and beg for him to suck him off again, take every bit of him into his mouth.

“How did you do it?” The question fills the silence and Sherlock knows what John’s asking without even looking up, his focus remaining on the newspaper as he asks, “What?”

“You know what I’m talking about. I’m fifteen centimeters-“

“Sixteen.”

“What?”

“You’re sixteen centimeters.” Sherlock finally looks up from the paper to find John staring at him in disbelief, his attempts to hide his growing erection with the laptop failing miserably.

“Did you deduce the size of my cock?!”

“No, I sucked your cock. I deduced the amount of time it would take for you to come.”

“Jesus Christ Sherlock, is everything always an experiment with you?”

Sherlock simply shrugs his shoulders, they both know the answer to that question, it’s silly to even ask what with the human liver currently occupying the microwave and all.

“It is to your benefit, John, although I’m still gathering the data.”

“Data, meaning…”

“Meaning in order to have an accurate set of data, multiple experiments need to be performed, variables changed.”

“So you want to…” John knows what Sherlock is saying, his cock knows what he’s saying, but he needs to hear the words straight forward from the detective’s mouth, not shrouded in scientific jargon.

“I want to suck your cock, John.”

With that the laptop that John had completely forgotten about clatters to the floor, his tongue reaching out to lick his suddenly dry lips, his cock twitching in his trousers. Sherlock takes it as an open invitation, folding the newspaper and setting it on the arm of his chair as he gets up and crosses the short distance between them, sinking to his knees between John’s legs that part with no hesitation.

John feels almost frozen in his spot, Sherlock making quick work of his hands as they slip the button from its confines and slide the zipper down. John lifts his hips far enough for his trousers and pants to be pulled just past his erection, Sherlock grabbing his hips and pulling him forward in the chair.

“Sherlock, the door is open, someone might come up.”

“Variables, John.”

The thought causes John’s erection to twitch with increased arousal, Sherlock’s hand grabbing him at the base and squeezing hard enough that John can’t tell if the strangled cry escaping his lips is from pleasure or pain. He reminds himself to be quiet, to not attract attention to their activities, but he knows it’s going to be hard, watching the look of concentration on Sherlock’s face as he pushes John’s erection up against the fabric of the bloggers shirt, his tongue tracing the underside of the sensitive skin until he reaches the head.

Though John doesn’t have a mind palace, he’s starting to think now would be a good time to create one, somewhere to catalog the images of Sherlock and that tongue, those lips, those hands. The way Sherlock keeps his eyes open, watches with his own fascination the responses John’s body makes with each little touch, each flick of the tongue.

John refrains from bucking his hips up when Sherlock travels back down the underside of his shaft, his nose brushing the sensitive skin ever so lightly before he finally reaches his scrotum, Sherlock making a mental note of the amount of time John has obviously spent making sure the area is neatly trimmed.

He continues to hold John’s cock against his stomach as he spends little time in the area, John struggling to keep his eyes open and on the detective as Sherlock slowly begins to slide his hand up and down the shaft, the movements painfully slow but the mixture of the sensations being caused by the simultaneous touch of his hand and tongue making his breath catch in his throat.

After a moment Sherlock pulls his mouth away, hand still in place as John groans from the loss, using the brief moment to take several deep breaths when he sees Sherlock eyeing the tip of his cock. The detective moistens his lips, pulling John’s cock away from his stomach as he suddenly takes the tip into his mouth, his tongue fucking the slit slowly, causing John’s eyes to roll back and a strangled moan of the detective’s name to leave his lips.

His whole body feels like it’s on fire with arousal, his fingers turning pale white as he grips the arm rests of the chair, knowing if he were to grab Sherlock’s head like before he may very well hurt him.

There’s a wet popping sound when Sherlock pulls back, releasing John’s cock head from his mouth, and the blogger feels like he can come instantly when Sherlock lets his gaze travel from his crotch to meet his eyes, John realizing that this is the first time they’ve actually looked at each other. 

The moment is fleeting, lasting only seconds before John watches his cock disappear into that skilled mouth again, Sherlock taking in a deep breath through his nose as the tip touches the back of his throat. 

When Sherlock swallows, John feels the contractions of his throat around him, unintelligible words leaving his lips as his head falls back onto the chair, his eyes closing tightly as his breath catches in his throat. He feels like he’s going to pass out, waves of pleasure coursing through his body, igniting every nerve ending. He’s trying to hold out but finds it hard as Sherlock hums a tune that he typically plays on the violin, the vibrations reverberating up the shaft of John’s cock.

He wants to tell Sherlock to stop, to keep going, to move something other than his vocal cords, but the ability to form words have been lost to him. Sherlock doesn’t need to be told though, he can read John’s body movements, feel the amount of restraint he’s putting into not completely puncturing the back of his throat. 

When he begins to slowly pull back, when the movement around his cock suddenly changes, John can’t handle it anymore, the metallic taste of blood coating his tongue as he bites back screaming Sherlock’s name, some faint voice in the back of his head reminding him of the open door.

Sherlock doesn’t swallow this time, his hand replacing his mouth around John’s cock as he wanks him. The amount of semen is definitely more than he remembers swallowing, coming out in what feels like endless spurts, coating his hand as well as John’s thigh and shirt. His free hand moves to push the shirt out of the way, his palm resting against his now bare abdomen as the muscles contract with his orgasm.

When he finally rides out the orgasm, John remains half sitting and half laying in the chair, his body limp with fatigue as he feels Sherlock cleaning him up with a serviette that was left behind by Mrs. Hudson on the tray with the tea and biscuits. He finds the smallest amount of energy to lift his hips when he feels Sherlock pulling his trousers back up, opening his eyes to see the detective focused on his task as he cleans up, disappearing into the kitchen behind John to wash his hands.

When he returns he grabs a cup of tea, returning to his chair and taking a seat as if nothing happened. John finally manages to pull himself back into a proper sitting position, his hands shaking ever so lightly as he reaches to grab his laptop off the floor, the forgotten computer reminding him of the conversation topic previously being discussed.

“You still didn’t tell me how you do it.”


	4. Chapter 4

John suddenly finds himself receiving blow jobs in the most random of places, sometimes at the most inappropriate times. Sherlock shows very little concern for being caught when he chases Lestrade from the room where a body is located, asking for five minutes alone to analyze the scene, but instead pushing John against the door, deep throating him and making him come in minutes.

He’s pretty sure that Lestrade is well aware just exactly what went on when the door finally opens and Sherlock ushers him in, John standing off to the side while trying to discreetly catch his breath, unconsciously feeling the front of his jeans to assure himself that Sherlock did in fact zip him up.

Sherlock seems unphased as usual as he deduces the scene in less than a minute, his tongue running along his lips ever so often, no doubt trying to capture any remaining taste John might have left behind. The sight almost always makes John’s cock twitch again, but obtaining an erection so soon after his first he finds is close to impossible, though Sherlock has tried plenty in the backseat of the cab on the way back to the flat.

The next time John finds Sherlock between his legs is in the alley that runs alongside Angelo's, Sherlock perched in an awkward kneel in front of him as he attempts to keep his knees from touching the ground, broken glass scattered around them. His fingers are buried in the detective’s hair, back pressed against the wall as he squeezes his eyes shut, the position all too common during their encounters.

When he finishes Sherlock stands up with a satisfied grin on his face, glancing at his watch as if he were timing himself, and for a fleeting moment John wonders if he is, realizing that he came considerably quicker than normal. When did that start happening?

As Sherlock straightens his jacket and turns to walk back towards the street, John quickly grabs his wrist and pulls him back towards him, switching their positions so that Sherlock’s back is against the wall. He wordlessly kneels in front of Sherlock, painfully realizing just how uncomfortable a position it is as he tries to balance himself, reaching forward to grab the zipper on Sherlock’s trousers.

Before he can succeed, Sherlock grabs him by the shoulders and pulls John to his feet, his eyebrow cocked up, a smirk on his face.

“What are you doing, John?” There’s humor in his voice, and John tries to look innocent, the attempt falling flat as a stupid grin plays at the corner of his lips.

“Returning the favor?”

He’s not sure himself whether it’s meant to be a comment or a question, not 100% sure what his plan really was. It’s not as if he has experience walking around putting other bloke’s cocks in his mouth the way Sherlock seems to, the detective clearly proving that John isn’t the first one he’s sucked off, that tongue way too skilled to be virgin.

“You’re not gay.” The statement is matter of fact, as if it’s the most obvious thing in the world, and John suddenly finds himself questioning it, wondering at what point between penetrating his throat and fondling his bullocks Sherlock has come to this conclusion. Of course he’s always denied people’s extreme need to point out that he’s gay, but he never much thought about Sherlock’s stance on the matter, assuming that he believed John to be just as gay as everyone else thought him to be.

“You’ve sucked my cock at least ten times over the past two weeks, Sherlock. I’ve _let_ you suck my cock. During which of those times did you suddenly decide that I rather be fondling a woman’s breasts rather than pulling your hair?” Is he really questioning his own sexuality?

“Would you feel better if I bent you over that trash can and shoved my cock up your ass until our bullocks were touching?” John doesn’t have to verbally answer, the look on his face is answer enough as Sherlock grins again, leaning in close to John’s ear, “variables” said in a whisper before the detective is walking off.

John stares after him for a moment, not quite sure what just happened. He has yet to consider where exactly this was going, if Sherlock planned on leaving the sexual activities in the one sided oral sex arena, or if he planned on accelerating his _experiments_ further. He’s starting to think he should have asked Sherlock just how far he planned on going with this, but he doubts he would have been given a straight answer, knowing Sherlock would probably have just responded that him knowing would change the variables too much.

John walks to the end of the alley when he notices Sherlock hailing a cab, and his attempts at continuing the conversation are shot down with one look from the detective. He considers pushing the subject, but finally decides against it when he considers the possibility that he would push it so much so that Sherlock stops his little experiment all together, and John is left having to palm himself again on a nightly basis.

When they return to the flat it’s late, Mrs. Hudson already well asleep, John’s feet dragging as they make their way up the stairs. It’s nights like these that John wishes he wasn’t so keen on following Sherlock around from body to body at all hours of the day, but considering his life without it, he realizes that he would be more miserable than he is with a few less extra hours of sleep at night.

When he bids Sherlock goodnight, it’s obvious that the detective has no intention of going to bed soon, seating himself behind his microscope at the table after hanging his coat up on the rack. John is used to the wordless wave of Sherlock’s hand before he makes his way up to his room, the door clicking softly as he closes it behind him.

With it being one in the morning, John finds no issue in falling asleep, his dreams a juxtaposition of cases playing side by side with the skillful things Sherlock does with his mouth during and after them. John typically finds himself being less surprised every morning when he wakes up with his pants sticking to him, the red material darkened where the ejaculate has escaped freely in the midst of his dreams.

When he wakes a few hours after falling asleep to the feel of his wet pants sticking to him once again, he's not surprised, the dream taking a turn when he finds his and Sherlock's roles reversed, John pushing him against the wall of a crime scene, ignoring Lestrade's presence as he sinks to his knees, foot accidentally kicking the hand of the dead body laying inches away from him as he consumes Sherlock's cock as if it's his lifeline.

What he is surprised to find is a dark material hovering inches from his face as he lay supine in his bed, the smell radiating from the fabric almost familiar. As his eyes travel down, the cloud of confusion starts to thin, noticing the transition of color from the black material to pale skin, the muscles contracting and relaxing with the movement of the man they belong to.

When John finally realizes what’s happening, that Sherlock is kneeled over him with his crotch in his face and his head hovering over John’s cock, he feels a slight sense of panic, his respirations increasing as he looks down between their bodies, catching the sight of Sherlock’s tongue just as it presses against the bulge in his pants, his mouth following quickly behind it as he sucks on John through the red material.

He’s not quite sure how to respond to this, realizing that Sherlock is wearing only his trousers as he straddles his head with his knees, an internal battle going on as John attempts to think through the movements of Sherlock’s tongue that has now moved down to his bollocks, the material of pants still very much in the way of getting what he really wants.

For a moment he just closes his eyes, tries to ride the pleasure of Sherlock slipping his hand under the waistband of the pants, his mouth still sucking on him through the material as his long fingers slip around the shaft, a tight squeeze of the base eliciting a moan from John.

When the motions continue and John finds himself trying to thrust into Sherlock’s hand and mouth, he notices the slight shift in the detective, each thrust causing Sherlock’s crotch to dip lower for a brief moment, the smell of his musk strong. He considers the reason behind Sherlock’s positioning, then remembers the conversation they had earlier in the evening when John attempted to _return the favor_. He wonders if that’s what this is, Sherlock changing his mind about wanting John to finally actively participate in the experiment, but he knows Sherlock better than that, knows that if he wanted something he would simply say it, the detective appearing more sexually dominant than most people give him credit for.

This is something else though, this is Sherlock giving John the choice. If he’s really intent on returning the favor, the opportunity is right in front of him, but if Sherlock is in fact right and he’s simply not gay, despite the current evidence of him attempting to thrust into Sherlock’s mouth and getting slightly upset by the material that still separates them, he can simply take what he wants from Sherlock and leave the rest where it stands.

He weighs his options, his eyes sliding open as he does so, his breath catching when he feels Sherlock finally push his pants down past his scrotum. He curses at Sherlock for not making this any easier on him, waking him up from a deep sleep to present him with this current predicament while also tongue fucking the slit of his cock.

As if Sherlock can sense his apprehension, John suddenly finds the detective’s lips moving to his inner thigh, his grip loosening on his shaft and causing John’s attention to focus only slightly better on what’s in front of him. When he’s finally able to regulate his breathing enough to keep himself from passing out, he decides to test the waters, his hands feeling almost numb as he reaches above him, letting them splay across the muscles of Sherlock’s abdomen, a small contraction being caused by the mixture of cold palms on warm skin.

John thinks he can feel Sherlock grinning into his thigh and finds himself pinching at the skin with the fingers of his right hand, Sherlock’s back arching as he lets his teeth dig into the skin, enough to make John startle at the unexpected response, but not enough to leave any sort of mark.

It’s as if a silent conversation is going on between the two, and John finds himself relaxing a bit as he moves his hands up Sherlock’s torso, trying to ignore the fact that it’s a flat chest with fine hair that he’s feeling instead of large breasts.

Sherlock mimics the pace in which John is going, his lips and tongue slowly making their way up his thigh, stopping to suck on a spot when John stops his hands at Sherlock’s chest, his thumbs rubbing over the nipples, the buds hardening to the cold touch. When John slides his hands to Sherlock’s sides and brings them back down, his back, Sherlock switches thighs and continues to mimic John’s movements, his tongue stopping just at the hem of John’s underpants as John’s hands stop at the edge of Sherlock’s trousers.

The nerves return to the pit of John’s stomach, and Sherlock can sense them, feel the tension in the man underneath him. After a moment of sucking a mark into the skin just inside John’s thigh, Sherlock finally allows his tongue to return to John’s shaft, the wet muscle swirling around the head several times, the action telling John that Sherlock isn’t going to withhold his pleasure just because John doesn’t feel comfortable going any further.

The feel of his cock sliding deep into Sherlock’s throat and the pressure being put on the underside of his testicles from the waistband of his underpants forces John to involuntarily put pressure on Sherlock’s lower back where is hands are resting, and Sherlock struggles to keep from burying his crotch in John’s face, knowing that the move was unintentional.

The feel of Sherlock’s muscles tightening under his touch causes John to thrust into Sherlock’s mouth, and Sherlock is surprised to find John’s hands traveling back around to his stomach, hesitation noted as they slowly maneuver to the button on the slacks, fingers fumbling a few times before he’s able to get it undone and slide the zipper down.

It’s clear by the sudden pause that John isn’t sure what to do next, and Sherlock fails to provide any guidance, allowing John’s actions to be 100% of his own accord. Though he wants to moan at the return of John’s hands to his skin, he keeps himself from doing so, the urge getting harder when hands slip under the waistband of both his trousers and pants, sliding under the material until John’s hands are cupped on Sherlock’s arse.

This time he can’t fight the sound that emanates from deep within him, and he finds himself pushing back into John’s hands as his pace on the blogger’s cock speeds up, one hand gripping the shaft and moving in motion with his mouth, the other fondling the bollocks, feeling them beginning to tighten in their grip.

John makes no move to go any further, quite content on where his hands are resting, gripping onto Sherlock as he closes his eyes and pants intelligible words, ignoring the fact that he’s essentially talking to Sherlock’s crotch. His mind can no longer focus enough to stop it, and he finds himself moaning into Sherlock’s crotch as he comes, only faintly noticing the spasm of the bulge still contained behind the material, his fingers leaving marks in the soft skin of Sherlock’s arse.

Sherlock waits for several moments for John to remember he’s clinging to him for dear life, and smirks when he hears a faint apology after he finally pulls his hands from Sherlock’s pants, the detective slowly swinging his leg back over John, pulling himself into a sitting position on the edge of the bed with his back to the blogger.

Nothing is said, both men trying to catch their breath, and they both decide that perhaps they like the new variables, Sherlock having to shift a little in his trousers when he stands up, a faint grin playing on his lips when he glances at John over his shoulder before leaving the room.


	5. Chapter 5

The next time Sherlock found himself with John’s cock in his mouth, he could tell that the blogger lacked the normal enthusiasm, his time to ejaculation increasing and his verbal appraisal of the detective’s skills falling flat. At some point between John waking up in a sixty-nine position and Sherlock sucking him off in the morgue of St. Barts, one of the variables had become unfavorable.

The ride back to the flat was a quiet one as Sherlock stole glances at John out of the corner of his eye, trying to deduce the sudden change in behavior. He didn’t like when experiments didn’t go in his favor, didn’t like the amount of time it usually took to change and assess the different variables to find out which was poisoning the rest of the experiment.

The only thing that had changed over their past few encounters was Sherlock giving John the chance to clarify his own feelings towards his sexuality, give him the chance to decide for himself if he wanted to interject his own variables into the experiment, and oh- Oh. Sherlock finally stopped stealing glances at John and simply turned his head towards the other man, John catching the detective’s reflection in the window that he’s been staring out of since they got into the cab. When he turns to look at Sherlock face to face he regrets it immediately, the corner of the detective’s lip turning up into a grin.

“What?”

Sherlock doesn’t bother answering John as the cab stops in front of 221B, the detective jumping out and leaving John to pay the tab as usual. When he finally catches up to him Sherlock is hanging his coat on the back of the door, his scarf following with an almost giddy look on his face. Though he should be used to the sudden mood changes by now, John feels an uneasiness settling in the pit of his stomach as Sherlock removes his coat for him, unsatisfied with the speed at which he is moving.

“Sherlock, what has gotten into you?”

“The experiment.”

The experiment. A response so vague that John can only watch as Sherlock paces around the room, giddy like a school girl, a full blown grin playing on his lips before he finally stops directly in front of John, the blogger only realizing that his back is against the wall when Sherlock’s face is mere centimeters from his own.

“The experiment, John. The variables.”

Sherlock rolls his eyes, the blogger can be so blind at times. He realizes John isn’t going to get it without an in depth explanation, so he does the next best thing he can think of, grabbing John’s face in his hands and closing the gap between them.

John stands frozen for a moment, allowing the tongue to snake into his mouth but not sure what else to do. Despite the very personal space of his mouth being invaded, Sherlock is managing to keep the distance between them, every inch of their body from the neck down remaining untouched by several centimeters.

The longer the kiss drags on, the more John finds his hands itching to grab the detective. He thinks he’s subtle when he finally lets them rest on Sherlock’s hips, his grip light. Despite almost feeling breathless, John allows the kiss to go on, only finally stopping when Sherlock pulls back, that obnoxious grin playing on his face once again.

John is tempted to ask again what the hell is going on, but he quickly realizes that any space that was previously between them is now lost, his body trapped between Sherlock’s and the wall, their chests heaving against each other as they attempt to rein in their breaths.

When he finally finds the energy to push Sherlock away he realizes the reason the gap between them was closed, and why Sherlock has a smug look on his face. He’s not quite sure at what point during the kiss his hands ventured away from his hips, but he feels his cheeks flush when he realizes that not only are they on his arse, but they’ve got a very firm grip on it, pulling Sherlock flush against him.

“Oh.”

Sherlock doesn’t move, allowing John to decide the next steps as they stand in silence. John isn’t sure how to react to the latest revelation that he very much likes the feel of Sherlock’s arse in his hands, but he feels disappointed when he lets them fall away, Sherlock taking a step back to give him some space.

When he still doesn’t say anything, Sherlock turns to walk towards his chair, the grin never leaving his lips as he feels John’s gaze following him. Before he can sit down he feels himself being turned back around, John pulling him back into another kiss, his hands immediately slipping down to his ass.

With his chair only centimeters behind him, Sherlock starts to pull John back but finds the other man resisting, causing the detective to start to pull away from the kiss. He thinks he’s pushing John past his limits, but realizes he’s wrong when John turns them around, their lips still locked as the back of his knees hit the edge of Sherlock’s chair, the detective carefully straddling John’s lap as the blogger sits down.

They’ve gone so far past the variables of the experiment but Sherlock has no intent of calling it off anytime soon, an unintentional moan escaping his lips when he feels John’s fingers at the button of his trousers, a faint tremor in his hands as he finally gets the button loose and pulls down the zipper.

He feels like John is starting an experiment of his own as his hands slip into the waistband of his pants, his hands finding Sherlock’s arse right away as he squeezes firmly, eliciting a moan from both men as he lets his head fall back against the chair, the kiss coming to a sudden stop. They’re both panting heavily, Sherlock trying to suppress his arousal when he realizes John is rolling his hips up against him, the bulge in his pants rubbing against Sherlock’s backside.

John seems off in his own world, his hands kneading the flesh of Sherlock’s arse as he ruts up against the detective, Sherlock’s mouth salivating, wanting the taste of John’s cock on his tongue. As he considers the logistics of meeting both of their desires, Sherlock feels a sudden rush of air in his lap and looks down with a sharp intake of breath, realizing that John has managed to pull his trousers down far enough to free his erection, the thick length moving in time with each of John’s thrusts up against him.

John is so caught up in his movements, eyes still closed, Sherlock’s name escaping his parted lips on a quiet breath, that he doesn’t notice the sudden presence between them.

After a moment of considering his next move, Sherlock finally decides to bring John back to the real world, his name coming out in a strangled moan on the first attempt, the second attempt coming out with more authority as John’s eyes suddenly snap open, his movements stilling.

For a moment he’s confused, and slightly embarrassed, his cheeks burning red as his hips still, his grip loosening on Sherlock’s arse. As he’s about to apologize he realizes that Sherlock is struggling to control his breathing, his gaze drifting down between them as John’s follows, the color draining from his face when he realizes what has got Sherlock gripping the top of the chair on either sides of his head.

“John, if we’re both going to get what we want, we’re going to have to move this to the bedroom.”

The words fall on deaf ears, the sound of John’s own body movements becoming deafening in his ears as he swallows, eyes fixed on something he never assumed he would ever see, Sherlock’s cock. In the amount of time he’s been doing his little experiment, John has yet to see Sherlock give himself pleasure, the bulge always noticeable though John tried to force it from his head.

He’s not sure what he expected, never took into consideration another male’s anatomy, but now with it in front of him he can’t help but look at it from two different angles: a clinical perspective, and a comparison to his own.

Sherlock’s length is slightly shorter than his own but he makes up for it in girth, the size impressive but not overwhelming. The shaft is slightly darker than the rest of Sherlock’s skin, and the thick head is moist with pre-cum, a drop sliding down the underside of Sherlock’s prick as John’s eyes follow it, his own cock twitching against Sherlock’s arse as he feels himself squeeze tighter than before, eliciting a moan from the man in his lap.

“John-“

“Shut up.”

Sherlock realizes just how much the blogger is concentrating when he’s suddenly cut off, the feeling leaving his hands as he grips the chair harder, his resolve ebbing away as he forces himself not to thrust himself against John, his head dropping until it’s resting against the side of Johns, breath hot on his neck.

When he feels the grip on his arse loosen, Sherlock feels himself letting out a sigh of relief, getting ready to climb off of John to move to the bedroom. His movements are cut short when one of the hands slides around his hip, stopping just inside his right thigh, his cock twitching when he realizes how close John is to touching him.

The tremor in the blogger’s hand increases as he slowly inches it up the inside of Sherlock’s thigh, his respirations increasing exponentially the closer he gets. He wants John to just get it over with, touch him, feel his hand sliding up and down the shaft, but the more he feels the man tense up underneath him, the more he realizes that John’s own experiment is falling flat, his eyes squeezed closed when Sherlock pulls away to look at him.

With his own hand steady, Sherlock grabs John’s wrist, the older man letting out what appears to be a sigh of relief. For a moment the flat is silent save for the deep breathing coming from both men, and Sherlock groans in discomfort as he climbs off of John’s lap, wordlessly turning and walking off down the hallway.

John thinks he’s expected to follow him but realizes he’s wrong when Sherlock turns into the bathroom, closing the door softly behind him as he disappears. He’s confused only for a moment before he looks down into his lap, realizing that the erection he was sporting before has gone soft, presumably at the sudden sight of another man’s cock in his lap.

**Notes for the Chapter:**

> I’m going to be honest, I’m not quite sure what happened there.


	6. Chapter 6

Days slowly lead into weeks, Sherlock seemingly forgetting all about the events of that night while John replays them on repeat in his head. In that quick moment of Sherlock climbing off of John’s lap and walking away, it seemed to mark the end of Sherlock’s little experiment, never bringing it up, never attempting to progress it, as if it never happened in the first place.

John finds himself vividly replaying the many instances of watching Sherlock on his knees in front of him, can almost feel the suction of the detective’s lips on his cock and he can’t help but feel his erection springing to life. It happens only at night as he lay in bed, attempting to wind down from a busy day at the surgery, only to find himself palming his erection and using the images of Sherlock sucking him off as fodder for his masturbatory activities. Many times he tries to concentrate on other sounds coming from the apartment, from Sherlock’s room below his, but just as he’s never once seen Sherlock give any attention to his own erection, he’s never capable of hearing the sound of the detective masturbating either.

The thought gives John an idea, and he feels his nerves firing on all ends as he releases his erection from his hand, pulling his pajama bottoms off as he slides off the bed and walks over to the door, completely nude.

The flat is silent, not uncommon for two am, but as John quietly makes his way down the stairs from his room, he hears a faint sound coming from the kitchen, followed by a quiet, frustrated sigh. When he peeks around the corner, he finds Sherlock sitting behind his microscope, his eyes closed as he rubs at his temples, clearly frustrated at whatever experiment he’s working on.

Without saying anything, John slips from around the corner, making no attempts at being quiet when he walks past the detective into the living room, feeling eyes suddenly on his back as he makes his way to his chair, giving no attention to Sherlock as he sits down, his erection standing proud, the pre-cum glistening on the head.

John counts silently in his head, waiting for Sherlock to acknowledge him as he stares blankly at the empty chair across from him _“3…2…1…”_

“What are you doing?” Sherlock’s voice is quiet, inquisitive, and John can almost visualize the look of intrigue on the detective’s face as he debates whether or not to approach the naked doctor. Perhaps Sherlock thinks he’s sleepwalking.

When John doesn’t answer, Sherlock finds himself walking slowly into the sitting room, almost in a predatory fashion, looking at the blogger from head to toe, taking in the sight of the hard cock his mouth has been watering for. He wants to sink between John’s spread legs, consume every centimeter of him, but the logical part of his brain is very much on guard at the moment and reminding him of the events that occurred last time.

“John-“

“Sit.”

The commanding tone in John’s voice sends jolts straight to Sherlock’s own cock, hesitating for only a split second before he finds himself sitting in his chair, John looking directly at him, almost in a curious way.

“I want to see you masturbate.”

With those few words, Sherlock finds his whole body stiffening up, his breath catching in his throat, and he can almost feel the beginnings of his erection starting to wilt within his pajamas, his palms suddenly getting sweaty as they rest on the arms of the chair.

“John, we both know this was a failed experiment.”

“Then I’m proposing a new experiment, to settle it once and for all. I want to watch you masturbate, if nothing happens, then we know we’re both right.”

The room is silent as Sherlock contemplates the proposal, his eyes taking in every bit of the naked man sitting across from him as he can, feeling himself stiffening at the site of the doctor’s erection. He closes his eyes as he tries to force himself to relax, listening to the sounds of his inhales and exhales, rubbing the sweat from his palms onto the armrest of the chair.

When he opens them again, John is very much focused on his movements, Sherlock attempting to figure out what the blogger is thinking but failing miserably. He already knows how this little proposed experiment with John ‘not gay’ Watson is going to end, with him standing over the sink in the bathroom, hand fisting his own erection, trying to ignore the look on John’s face when he realized he was-

Sherlock’s thoughts stop with a sudden jolt, his eyes snapping open when he feels the fingers on his skin, gently touching the area above the waistband of his pajama bottoms. He doesn’t realize he’s stopped breathing, his mind getting fuzzy around the edges as John hooks his fingers in the waistband, Sherlock’s hips lifting up automatically as his legs are exposed to the cool air.

“Masturbate.”

Sherlock finally releases the air he’s been holding in as he feels a moan escape from deep within his throat, watching John sink to his knees in front of him, just out of his reach so that they’re not making any contact. It’s hardly comforting, but Sherlock’s body makes it evident that it cares very little as his erection twitches, his hips shifting slightly upwards as he closes his eyes again and wraps his hand around the base of his hardened cock, trying to forget the eyes that are currently on him.

Other than the one incident of Mycroft walking in on him when he was younger, Sherlock has never masturbated while anyone watched, let alone sat so close to him that he could feel the light ghosting of John’s breath on his inner thigh. As he allows his hand to glide up to the head, thumbing the slit, Sherlock can only fleetingly wonder what caused John to want to see this, knowing his affinity to denying his closeted sexuality.

The thought is gone before he can ponder it, however, as his hips buck up violently and he feels a hand close over his, his breaths coming out in short gasps as he lets his eyes slide open, taking in the focus on John’s face as he leans forward, concentrating on his movements as he takes over the rhythm of strokes, speeding up Sherlock’s hand.

The erection hanging between John’s legs isn’t exactly as swollen as when he initially walked in, but it is definitely still present as Sherlock unconsciously slides himself forward in the chair, noticing John’s lack of movement as the detective’s cock stops just short of his face.

For a moment it feels like a stand-off, their hands stopping, John’s breath catching in his throat as he stares at the impressive erection in front of him, one hand covering Sherlock’s while the other rests on the detective’s thigh. For a split second Sherlock thinks that John is going to close the gap between lips and cock, but he quickly realizes John is locked in a battle with himself as his hand loosens from Sherlock’s cock, the other dropping from his thigh.

The tension suddenly pours from John’s body, and Sherlock finds himself sighing dramatically as he pushes John’s hand away from his, the blogger looking confused and slightly panicked as he’s pulled to his feet and pushed backwards, almost faltering but instead landing in his chair behind him.

Without a word, Sherlock straddles John’s hips, their erections rubbing together and causing John to let out a quit gasp, his hands grabbing the arms of the chair as he stares up at the man in his lap. He opens his mouth to say something, anything, but Sherlock ignores it as he leans forward, capturing John in a heated kiss as his hands slide down the bloggers arms, stopping at his hands as he pulls them from the arm rest and places one on his ass, the other coming between their bodies as Sherlock pulls away from the kiss.

“Sherlock.” The word comes out in a strangled gasp as John suddenly finds two of his fingers enclosed in the warmth and wetness of Sherlock’s mouth, the detective’s tongue coating the digits in a thick layer of saliva before he pulls them out and pushes his hand between their bodies, bollocks brushing against his hand as Sherlock releases his grip with John’s fingers just at his tight entrance.

The ball is in John’s court, his chest tightening and his respirations stopping as he closes his eyes. He feels the saliva on his fingers drying and knows he has to make a quick decision on what to do, but then he feels Sherlock grabbing both of their erections together in one hand and he finds himself unconsciously thrusting his fingers up, a pleased sound coming from Sherlock as John finally lets his eyes slip open.

His fingers are buried deep within Sherlock, the detective’s eyes closed and lips slightly parted as he grabs John’s shoulder with his free hand, the grip tight enough to leave a mark as he slowly pulls up and then forces himself back down, the motion slow but more than pleasurable for both men.

There’s far from any question on John’s enjoyment in the activity as Sherlock begins to stroke their cocks together, John’s head falling back against the chair as he watches Sherlock over him, revels in the feel of the tightness of his fingers, tighter than any woman he’s felt before.

The thought makes his cock twitch in Sherlock’s hand, and the blogger removes his fingers only to replace them with a third with no prompting, a bead of sweat sliding down the ridges of Sherlock’s spine before slipping between his crack and landing on John’s hand.

John considers the times he’s had a woman in his lap, his fingers inside them, stretching them before they lowered themselves onto his impressive cock, but this is very much different as he watches Sherlock, sweat beading across both of their brows as the detective’s eyes remain closed, concentrating, small puffs of air coming out with each thrust down onto John’s fingers.

The grip on Sherlock’s ass lessens as John slides it around his waist, watching the detective’s eyes slip open as the touch moves up his chest and around his neck, the bloggers grip firm as he pulls Sherlock towards him and their lips meet in a messy collision of tongues and pornographic moans.

After a moment Sherlock pulls away, his chest heaving as he drops his head, John wondering what he’s doing only for a second before he feels the wetness of Sherlock’s spit on his erection, the detective removing his own cock from his hand before focusing solely on John’s, spreading the saliva down the shaft before pulling himself up off the blogger’s fingers, repositioning himself so John’s thick head twitches against his entrance.

This time Sherlock doesn’t wait for John to make the move, lowering himself until he’s filled to the hilt, his eyes finally meeting John’s as the blogger lets his head fall back again. His hands rest on Sherlock’s thighs, thumbs splayed wide as they press into the crease of the detective’s groin, his rapid pulse present in the femoral arteries that lay just below the blogger’s thumbs.

The movement is clumsy at first as they try to find their rhythm, Sherlock gripping the head of the chair on either side of John’s head as he rides his cock, their moans and grunts surely audible in Mrs. Hudson’s flat. He tries to duck his head down to capture John’s lips, but their movements are too frantic, too concentrated on the pleasure as Sherlock feels a hand suddenly wrap around his erection, stroking in time with the thrusts, foreheads pressed against each other as eyes remain closed.

It doesn’t take long before both of their bodies are shuddering with pleasure, John’s hand becoming coated in Sherlock’s semen as the detective feels the blogger’s cock pulsating within him, cum following the softening prick as he pulls out of Sherlock and grabs his ass firmly with both hands, pulling their bodies together as their lips finally meet again.

Its several minutes before they’re able to get their breathing under control again, their pulse rates slow to come down as Sherlock sits back in John’s lap.

“I think the experiment was inconclusive.” John looks confused by Sherlock’s words for only a moment before a wide grin spreads across his face, understanding setting in.

“I think you’re right, perhaps we should change the variables slightly. Your bed or mine?”

**Notes for the Chapter:**

> And they fucked happily ever after. The end.


End file.
